Federal investigators say a truck driver who crossed a runway at Boston's Logan International Airport seconds before a jet took off behind him told them he didn't know the runway was open.
The preliminary report filed by the National Transportation Safety Board last week says the driver wasn't in contact with air traffic controllers and wasn't cleared to cross.
The truck was seconds away from colliding with a US Airways flight carrying 89 people to Phoenix.
The Massachusetts Port Authority runs Logan, one of the nation's busiest airports. It has stopped construction around the runway until an investigation into the incident is completed.